To what extent is a Murabaha contract legitimate if it includes a promise to sell goods that the bank (first party) purchases at the request of the client (second party), then the client receives them as an agent for the bank, and the client commits to purchasing them from the bank with deferred payment, and the price is determined later?

The mentioned clauses represent a promise between the purchasing agent and the bank, which is permissible. The bank is allowed to take a seriousness deposit (earnest money) from which the actual damages incurred can be recovered if the purchasing agent defaults. The bank's authorization of the purchasing agent to receive the goods is permissible. Article Three of the contract is unclear, but the goods, at the stage of the promise and before being sold by the bank to the client, have not entered into the client's guarantee. Stipulating their guarantee upon him is invalid unless he was an agent for the bank and was negligent or transgressed. Stipulating financial penalties for procrastination in paying installments and donating them is forbidden.